Can I ask questions about a Supra?

Now I know that this is technically a correct craft site, but will you guys object too much if I ask questions about a Supra?

I have a 89 Supra Mariah with a PCM 351 Ford and a PCM power plus tranny. I have had the boat for little more than a year, and I am still trying to figure this inboard stuff out. The boat has a very dubious history, and I like to do things myself.

Needless to say, Dubious boat, no knowledge, and DIY is a dangerous combination.

The reason I want to post here is that it seems like this forum is full of people who like old inboards and like DIY. I have found many helpful discussions searching this site, and I couldn't find a comparable old supra site. I don't know why that is, maybe old supras just were not that popular. Or maybe they are here, just pretending to have Correct Crafts.

Jared
      

Ask away. You may get a little ribbing (this is CC fan afterall). However, we have active members with American Skiers, Malibus, Centurions, and Supremes. I'm sure a little Supra talk won't hurt anyone. BKH

So what's the question??? As long as you're not trying to sell Viagra, Cialis or Herpecine you won't be turned away.

If there is a question in there, I'd say you are putting you trailer too deep in the water. If you don't put it in so far, the boat should engage the bunks and lift the nose up above the black roller. BKH

Last summer I also replaced the starter, the t-stat and the fuel filter.

Then I found ski-dim, and bought a distributor kit (cap, rotor, points) and learned how to use a dwell meter.

Once I did that, the boat actually ran good for the rest of last summer, although I am not sure if I am getting the top end I should-- the RPM's max out pretty low. But it goes fast enough for me.

I think I could really use a carb rebuild. And I am now worried a bit about my cooling system. That will be the next post.

Jared

     

So that brings us up to last week.

I started the boat up for the first time this year on saturday. I immediately had several problems.

First, I immediately noticed that it wasn't sucking water up (the strainer was staying empty). I quickley turned off the boat, and after some examination realized that the the drain valve for the tranner cooler wasn't shut, so the pump was sucking air.

I was worried about by impeller, but the impeller was very new (replaced late last summer)and it had only been run dry for a few seconds.   

So I started the boat up again, and this time it sucked up water. However, as it idled the temp started to rise above its normal range. I shut it off when it reached about 195. This made me wonder if I had ruined the impeller (or if it had gone bad sitting over the winter.

I then went and replaced the shaft packing with some gore tex stuff I got from ski dim. I was worried that this was going to be hard, but it was really pretty easy. The only question I had was how tight to tighten it. I did it hand tight, but as hand tight as I could get it with one hand.

So then I went back to cooling problem. I decided to start the boat up one more time. This time, the boat heated up to 160 degrees and then stopped heating up. It appeared to be cooling just fine.

I let it idle for a few minutes while I measured the alternator output and stuff. But then I noticed that there was smoke rising from the big hoses down stream of the exhaust manifold risers. I checked the temp again, and it was at 160 degrees.

So I turned off the boat. The risers were cool to the touch, but the big hoses connected to them were very hot -- to the point of smoking. And the whole time the boat was just idling.

I don't understand this.

I am thinking I will just break down and replace the impeller again (I already have one) and maybe even get a new t-stat from skidim (but I am not sure if I want a 143 degree or a 160 degree t-stat).

But I still don't understand how the risers can be cool, and the hoses behind them hot and smoking.

Any ideas?

Jared

PS: Notice it only took five posts and ten pictures before I finally got around to asking a question? Are you sure you want to let a Supra guy in?

87BFN owner wrote: Where you getting water out of the hoses? If so how much? How long did you let the boat idle, it will take a couple minutes for the cast iron risers to get hot as water is passing through them. The exhaust hoses however will get hot much faster if you don't have enough water moving through them.

There was lots of water coming out the exhaust, if that is what you mean.

I am pretty sure the hose was nearly all the way on, although maybe it wasn't.   I guess how much water that provides depends on the level of water pressure.

Your explanation on why the exhaust hose would heat up before the riser makes sense. So maybe it really is that simple-- maybe I didn't have enough water pressure on.

So, when you run an inboard off a fake-a-lake, should you turn the water pressure on full blast? I know with an I/O they said you weren't supposed to.

Jared

sjpitts, why is there dirt, sand and stones on the prop guard of your trailer?

I think you've got an air bubble in the system the first try and a low water flow the second time. But the water hose in a bucket and an hose from the waterstrainer. Let the engine pump the water out of the bucket this way. Normally when idling the water hose cannot get sufficient water in the bucket (in my 6 boats experience). When this happens, you know the watersystem is sucking enough water.

I think you're fine, just get enough water in the engine when running on dry land. The pump sucks at 2000rpm easily a 5 gallons bucket empty within seconds. Watch the temp gauge!

Welcome. As an owner of an American Skier I can vouch for all these guys. Great group so don't be afraid to ask away.

First off, Fake-A-Lake is turned on full blast. Don't rev the engine above 2K RPM though. Also my recommendation is that you replace the impeller when you pull it out of storage for upcoming season instead of when you put it to bed for the winter. The impeller blades could take a "set" after being frozen all winter. I always did that and changed the fuel filter/water seperater in the spring. I agree with others. I think the engine is fine and the issues you're experiencing are just learning experiences being a new inboard owner. I think the impeller was partly to blame the first time (getting the "set" worked out of it) and the second was insufficient water pressure.

Good luck and let us know how things work out for you.

David F wrote: If it were me, I would remove the hoses and check them out. Also, it appears the risers have been removed and gooped up with sealant on re-install. It si common that the new gasket is installed incorrectly (backwards). You should remove the risers and check this out as well. The blocked water passage on the gasket should be toward the outlet (rear).

If I were to pull the exhaust hoses for a check, would I need to totally remove them? Or just pull off one end? And what exactly would I be looking for?

Although I don't really think it is an issue. They were hot, but I could still put my hands on them. Although they did smoke some.

Thanks again

Jared

Thanks for the input. As you can tell, I really need the help.

I have wanted to replace the manifolds and risers, but I had hoped they would last a couple more years.

Here are some pictures of the manifolds in question. Can you really tell that they need to be replaced? The stains on the side is enough to know? Is there some sort of test? Would I need to replace both the manifold and the risers, or maybe just the risers?

I will note that the manifolds with the most stains are not on the side with the low compression. I can link to higher resolution pictures if these are not good enough.

Thanks again.

Jared

sjpitts wrote: 81nautique wrote: If the riser gaskets haven't been replaced as Dave suggests you need to get that done as they appear to be leaking and could be an explanation of the rusty cylinder walls. Wait, just the gaskets? Not the risers themselves? That seems like it might be easy to do. Please tell me more. Thanks Jared

Hard to tell from the pics if the gaskets have ever been replaced but the bolts are still painted and don't look like they've ever been removed. They are certainly leaking on the outside and probably on the inside as well. Gaskets are less than $10 each or you can get a service kit from skidim for about $90. The kit comes with riser gaskts, manifold gaskets, 90 degree fittings, brass drain plugs and all new bolts. Thats just regular main. that needs to be done.

Riley wrote: If they are leaking on the inside, does that mean water can get into the engine? After 20 years is replacing the gaskets something to consider?

Yes, and yes. You dont want water getting back down into the cylinders- its a cheap and easy fix.

Mark Mel wrote: I have the riser gaskets from DIM to put on mine. Do I put them on dry or should I use some sort of RTV or gasket sealant?

Put em on dry Mark, the new gaskets seal up real good. Make sure you spray the bolts with penetrating oil a day or so before and work them free slowly back and forth. They will snap pretty easily so tread lightly and replace them with new.